1. Field of the Invention
This invention relates to an electrode assembly for metal oxide reduction, and more specifically, this invention relates to a method and device for continuous replenishment of consumable anodes during electrolytic reduction of metal oxides.
2. Background of the Invention
Electrolysis drives a myriad of non-spontaneous processes, including the generation of hydrogen from water, reclamation of metal from their salts and oxides, and redox reactions generally. For example, electrochemical processes recover high purity metal/metals from waste feeds or ores. Aluminum production is one instance. Reclamation of uranium from used nuclear fuel is another.
Uranium metal reclamation via electrolysis requires specialized conditions, including the use of a molten salt (500-650° C.) electrolyte bath, an inert atmosphere environment, and a remotely operated facility if the uranium has been irradiated. Hazardous off-gases are also generated during electrolysis, including, but not limited to CO, CO2, O2 and Cl2, and combinations thereof.
A myriad of systems and methods exist for subjecting used nuclear fuel to redox reactions associated with electrolysis. Unfortunately, there are drawbacks to many of these systems. For example, the size and bulk of the anodes becomes a limiting factor as to how long the process can continue. Once the anodes are consumed, the process needs to be stopped and new anodes installed before reassembly and start-up can occur.
In other applications, non-consumable anodes fabricated from precious metal are used. This substantially increases the cost of the conversion process, especially if the anode is consumed during an off-normal cell operation. In addition, this possibility necessitates implementing a secondary protective circuit to avoid anode failure.
A need exists in the art for an anode assembly in electrolytic systems that does not need constant, direct hands-on supervision. The system should allow continuous redox processes by automatically deploying replacement anodes into an electrolyte (for example via gravity) without the need to first remove the assembly from the salt bath or otherwise shut down the reaction. Further, the system should effectively remove or otherwise manage any corrosive off-gases while confined to hot-cells, gloveboxes, and/or other enclosures.